Gas turbine fuel oil and production method thereof and power generation method

Abstract

Feed oil is subject to atmospheric distillation, to thereby be separated into light oil or light distillate and atmospheric residue oil. The light distillate is catalytically contacted with pressurized hydrogen in the presence of a catalyst, resulting in a first hydrotreating step being executed. In this instance, various fractions of the light distillate produced in the atmospheric distillation are subject to hydrotreating in a lump. The atmospheric residue oil is then separated into a light matter and a heavy matter. The light matter is subject to second hydrotreating in the presence of a catalyst to produce refined oil (light matter), which is mixed with refined oil produced in the first hydrotreating to prepare a mixture. The mixture is used as gas turbine fuel oil.

Description

TECHNICAL FIELD[0001]This invention relates to fuel oil for a gas turbine, and more particularly to gas turbine fuel oil used for power generation by gas turbine, a method for producing such gas turbine fuel oil and a power generation method using such gas turbine fuel oil.BACKGROUND ART[0002]In general, oil thermal power generation is adapted to generate steam at a high pressure in a boiler using crude oil and / or heavy oil as a fuel for the boiler, to thereby rotate a steam turbine by means of the thus-generated steam, leading to power generation. However, such a system is deteriorated in power generation efficiency. Currently, a high-efficiency large-sized oil-fired boiler is developed, however, it merely exhibits generation efficiency as low as about 40%. Thus, it causes a large part of energy to be outwardly discharged in the form of greenhouse gas without being recovered. In addition, it causes a certain amount of SOx to be present in exhaust gas or flue gas discharged therefro...

AI Technical Summary

Benefits of technology

[0009]Accordingly, it is an object of the present invention to provide a method for producing gas turbine fuel oil which is capable of producing gas turbine fuel oil from feed oil with increased efficiency.

[0011]In accordance with one aspect of the present invention, a method for producing gas turbine fuel oil from feed oil with increased yields is provided. The method includes an atmospheric distillation step of subjecting crude oil acting as the feed oil to atmospheric distillation to separate the crude oil into light oil and atmospheric residue oil, a first hydrotreating step of contacting the light oil produced in the atmospheric distillation step with pressurized hydrogen in the presence of a catalyst in a lump, to thereby carry out an impurity removal treatment, resulting in obtaining refined oil, and a first separation step of separating the atmospheric residue oil into a light oil matter and a heavy oil matter. The first separation step is selected from the group consisting of vacuum distillation, solvent deasphalting, thermal cracking and steam distillation. The method also includes a second hydrotreating step of contacting the light oil matter produced in the first separation step with pressurized hydrogen in the presence of a catalyst, to thereby carry out an impurity removal treatment, resulting in obtaining refined oil. Gas turbine fuel oil obtained in the first and second hydrotreating steps is 4 cSt or less in viscosity at 100° C., contains alkaline metal in an amount of 1 ppm or less, lead (Pb) in an amount of 1 ppm or less, V in an amount of 0.5 ppm or less, Ca in an amount of 2 ppm or less and sulfur in an amount of 500 ppm or less, and is produced with yields of 65% or more based on the feed oil.

[0014]Thus, in the present invention, the first hydrotreating is carried out subsequent to the atmospheric distillation, so that the atmospheric distillation may be executed while taking no notice of the amount of sulfur and metal entering the light oil matter. Also, practicing of the second hydrotreating step after the first separation step permits conditions for the first separation step to be determined so as to increase the amount of light oil matter produced, irrespective of sulfur and metal, so that the gas turbine fuel oil may be produced with increased yields based on the feed oil. The present invention is aimed at gas turbine fuel oil; thus, the first hydrotreating is executed merely by subjecting a plurality of light oil fractions produced in the atmospheric distillation column to hydrotreating in a lump, resulting in a cost of equipment being reduced.

[0020]Also, in accordance with this aspect of the present invention, a method for producing gas turbine fuel oil from feed oil with increased yields is provided. The method includes a first separation step of separating heavy feed oil consisting of atmospheric residue oil obtained by atmospheric distillation of crude oil and / or heavy oil into a light oil matter and a heavy oil matter. The first separation step may be selected from the group consisting of vacuum distillation, solvent deasphalting, thermal cracking and steam distillation. Also, the method includes a second hydrotreating step of contacting the light oil matter produced in the first separation step with pressurized hydrogen in the presence of a catalyst, to thereby carry out an impurity removal treatment, resulting in obtaining refined oil. The gas turbine fuel oil which is refined oil thus obtained is 4 cSt or less in viscosity at 100° C., contains alkaline metal in an amount of 1 ppm or less, lead in an amount of 1 ppm or less, V in an amount of 0.5 ppm or less, Ca in an amount of 2 ppm or less and sulfur in an amount of 500 ppm or less, and is produced with yields of 40% or more based on the heavy feed oil.

[0024]Thus, in the present invention, crude oil is subject to the atmospheric distillation, to thereby be separated into light oil or light distillate and atmospheric residue oil. The light oil is then hydrotreated and the atmospheric residue oil is subject to the separation treatment or hydrotreating, resulting in a light oil matter being produced. The light oil matter thus obtained is then subject to hydrotreating, to thereby provide refined oil, which is used as the gas turbine fuel oil. Thus, the present invention permits the gas turbine fuel oil to be produced with increased yields while ensuring high quality of the fuel oil.

[0026]In addition, in accordance with a further aspect of the present invention, a power generation method is provided. The power generation method includes the steps of driving a gas turbine using gas turbine fuel oil produced as described above as fuel therefor to carry out power generation and using high-temperature exhaust gas discharged from the gas turbine as a heat source for a waste heat recovery boiler and driving a steam turbine by means of steam generated in the waste heat recovery boiler, resulting in power generation being carried out.

Problems solved by technology

However, such a system is deteriorated in power generation efficiency.

Thus, it causes a large part of energy to be outwardly discharged in the form of greenhouse gas without being recovered.

In addition, it causes a certain amount of SOx to be present in exhaust gas or flue gas discharged therefrom.

Although the exhaust gas is subject to flue gas desulfurization, SOx is partially discharged to an ambient atmosphere, leading to environmental pollution.

Unfortunately, this leads to an increase in cost of equipment.

Now, an environmental problem comes to notice in the art.

Unfortunately, in power generation using gas turbine fuel oil, arrangement of the flue gas desulfurization unit causes a deterioration in power generation efficiency due to a pressure loss, so that it is required to minimize a sulfur content of gas turbine fuel oil.

Thus, the techniques of the former Japanese publication cause the amount of firing of oil to be considerably restricted in the atmospheric distillation or vacuum distillation, to thereby fail to increase the amount of light oil or light distillate to be fed to the gas turbine or the amount of gas turbine fuel oil.

Also, when it is applied to crude oil which is readily available and increased in sulfur content, recovery of light oil or light residue in the same amount causes a sulfur content of the light oil to exceed a specified level, so that it is unsuitable for use as fuel oil for a gas turbine.

Thus, it is forced to decrease recovery of the light oil, resulting in application to the crude oil being technically and economically disadvantageous.

However, the techniques are constructed so as to treat crude oil at a low sulfur content, so that application of the techniques to crude oil at a high sulfur content is considerably restricted.

Unfortunately, this causes excessive cracking of light oil in the crude oil, resulting in LPG or the like being contained in a large amount in fuel oil for a gas turbine, so that storage of the fuel oil causes a part thereof to be gasified.

Also, the reaction temperature and reaction pressure are caused to be increased, so that a reaction vessel for the hydrotreating is complicated in structure and increased in manufacturing cost.

Further, an increase in reaction time requires large-sizing of a catalyst carrier, leading to large-sizing of the reaction vessel and an increase in consumption of a catalyst.

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